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  • Metabolism and Body Weight
    Metabolism and Body Weight (OpenStax Psychology 2e) Our body weight is affected by a number of factors, including gene-environment interactions, and the number of calories we consume versus the number of calories we burn in daily activity. If our caloric intake exceeds our caloric use, our bodies store excess energy in the form of fat. If we … Continue reading Metabolism and Body Weight
  • Maslow’s Hierarchy of Needs
    Maslow’s Hierarchy of Needs (OpenStax Psychology 2e) Abraham Maslow (1943) proposed a hierarchy of needs that spans the spectrum of motives ranging from the biological to the individual to the social. These needs are often depicted as a pyramid (Figure 1). At the base of the pyramid are all of the physiological needs that are necessary for survival. These are followed … Continue reading Maslow’s Hierarchy of Needs
  • Pre-Print Research Highlights: The Entire Human Genome Has Been Sequenced
    The Entire Human Genome Has Been Sequenced June 2, 2021 The International Human Genome Sequencing Consortium and Celera Genomics published the initial drafts of the human genome in 2001. The initial human genome publication revolutionized the field of genomics. The drafts and the follow-up updates covered the euchromatic part of the genome. However, many other complex regions … Continue reading Pre-Print Research Highlights: The Entire Human Genome Has Been Sequenced
  • pH and pOH
    OpenStax Chemistry 2e Hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water (Kw). The concentrations of these ions in a solution are often critical determinants of the solution’s properties and the chemical behaviors of its other solutes, … Continue reading pH and pOH
  • Brønsted-Lowry Acids and Bases
    Bronsted-Lowry (OpenStax Chemistry 2e) The acid-base reaction class has been studied for quite some time. In 1680, Robert Boyle reported traits of acid solutions that included their ability to dissolve many substances, to change the colors of certain natural dyes, and to lose these traits after coming in contact with alkali (base) solutions. In the eighteenth century, it was … Continue reading Brønsted-Lowry Acids and Bases
  • The Effect of a Catalyst
    The Effect of a Catalyst (OpenStax Chemistry 2e) The catalyst is a substance that enables a reaction to proceed via a different mechanism with an accelerated rate. The catalyzed reaction mechanism involves a lower energy transition state than the uncatalyzed reaction, resulting in a lower activation energy, Ea, and a correspondingly greater rate constant. To discern the effect of … Continue reading The Effect of a Catalyst
  • Physiological Mechanisms
    Physiological Mechanisms (OpenStax Psychology 2e) There are a number of physiological mechanisms that serve as the basis for hunger. When our stomachs are empty, they contract. Typically, a person then experiences hunger pangs. Chemical messages travel to the brain, and serve as a signal to initiate feeding behavior. When our blood glucose levels drop, the pancreas and … Continue reading Physiological Mechanisms
  • Equilibrium and Soft Drinks
    Equilibrium and Soft Drinks (OpenStax Chemistry 2e) The connection between chemistry and carbonated soft drinks goes back to 1767 when Joseph Priestley (1733–1804) developed a method of infusing water with carbon dioxide to make carbonated water. Priestley’s approach involved the production of carbon dioxide by reacting oil of vitriol (sulfuric acid) with chalk (calcium carbonate). The carbon … Continue reading Equilibrium and Soft Drinks
  • Equilibrium Constants
    Equilibrium Constants (OpenStax Chemistry 2e) The status of a reversible reaction is conveniently assessed by evaluating its reaction quotient (Q). For a reversible reaction described by the reaction quotient is derived directly from the stoichiometry of the balanced equation as where the subscript c denotes the use of molar concentrations in the expression. If the reactants and products … Continue reading Equilibrium Constants
  • Chemical Equilibria
    Chemical Equilibria (OpenStax Chemistry 2e) The convention for writing chemical equations involves placing reactant formulas on the left side of a reaction arrow and product formulas on the right side. By this convention, and the definitions of “reactant” and “product,” a chemical equation represents the reaction in question as proceeding from left to right. Reversible reactions, however, may … Continue reading Chemical Equilibria
  • Enzyme Structure and Function
    Enzyme Structure and Function (OpenStax Chemistry 2e) The study of enzymes is an important interconnection between biology and chemistry. Enzymes are usually proteins (polypeptides) that help to control the rate of chemical reactions between biologically important compounds, particularly those that are involved in cellular metabolism. Different classes of enzymes perform a variety of functions, as shown in Table … Continue reading Enzyme Structure and Function
  • Automobile Catalytic Converters
    Automobile Catalytic Converters (OpenStax Chemistry 2e) Scientists developed catalytic converters to reduce the amount of toxic emissions produced by burning gasoline in internal combustion engines. By utilizing a carefully selected blend of catalytically active metals, it is possible to effect complete combustion of all carbon-containing compounds to carbon dioxide while also reducing the output of nitrogen oxides. … Continue reading Automobile Catalytic Converters
  • Research Highlights: A Histone Variant Has Multiple Roles in Transcriptional Regulation
    A Histone Variant Has Multiple Roles in Transcriptional Regulation May 29, 2021 A promoter is a site on DNA to which the RNA polymerase can bind to initiate the transcription.[1] Chromatin accessibility of a promoter is necessary for the regulation of transcriptional activity. Histones are proteins that provide structural support to a chromosome.[2] Long DNA molecules are … Continue reading Research Highlights: A Histone Variant Has Multiple Roles in Transcriptional Regulation
  • Heterogeneous Catalysts
    Heterogeneous Catalysts (OpenStax Chemistry 2e) A heterogeneous catalyst is a catalyst that is present in a different phase (usually a solid) than the reactants. Such catalysts generally function by furnishing an active surface upon which a reaction can occur. Gas and liquid phase reactions catalyzed by heterogeneous catalysts occur on the surface of the catalyst rather than within the … Continue reading Heterogeneous Catalysts
  • Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency
    Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency (OpenStax Chemistry 2e) Enzymes in the human body act as catalysts for important chemical reactions in cellular metabolism. As such, a deficiency of a particular enzyme can translate to a life-threatening disease. G6PD (glucose-6-phosphate dehydrogenase) deficiency, a genetic condition that results in a shortage of the enzyme glucose-6-phosphate dehydrogenase, is the most common … Continue reading Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency
  • Homogeneous Catalysts
    Homogeneous Catalysts (OpenStax Chemistry 2e) A homogeneous catalyst is present in the same phase as the reactants. It interacts with a reactant to form an intermediate substance, which then decomposes or reacts with another reactant in one or more steps to regenerate the original catalyst and form product. As an important illustration of homogeneous catalysis, consider the earth’s ozone … Continue reading Homogeneous Catalysts
  • The Catalysis
    The Catalysis (OpenStax Chemistry 2e) Among the factors affecting chemical reaction rates discussed earlier in this chapter was the presence of a catalyst, a substance that can increase the reaction rate without being consumed in the reaction. The concepts introduced in the previous section on reaction mechanisms provide the basis for understanding how catalysts are able to accomplish … Continue reading The Catalysis
  • Relating Reaction Mechanisms to Rate Laws
    Relating Reaction Mechanisms to Rate Laws (OpenStax Chemistry 2e) It’s often the case that one step in a multistep reaction mechanism is significantly slower than the others. Because a reaction cannot proceed faster than its slowest step, this step will limit the rate at which the overall reaction occurs. The slowest step is therefore called the rate-limiting step (or … Continue reading Relating Reaction Mechanisms to Rate Laws
  • Bimolecular Elementary Reactions
    Bimolecular Elementary Reactions (OpenStax Chemistry 2e) A bimolecular reaction involves two reactant species, for example: For the first type, in which the two reactant molecules are different, the rate law is first-order in A and first order in B (second-order overall): For the second type, in which two identical molecules collide and react, the rate law is second order in A: Some chemical reactions … Continue reading Bimolecular Elementary Reactions
  • Unimolecular Elementary Reactions
    Unimolecular Elementary Reactions (OpenStax Chemistry 2e) The molecularity of an elementary reaction is the number of reactant species (atoms, molecules, or ions). For example, a unimolecular reaction involves the reaction of a single reactant species to produce one or more molecules of product: The rate law for a unimolecular reaction is first order: A unimolecular reaction may be one of several elementary reactions … Continue reading Unimolecular Elementary Reactions
  • Activation Energy and the Arrhenius Equation
    Activation Energy and the Arrhenius Equation (OpenStax Chemistry 2e) The minimum energy necessary to form a product during a collision between reactants is called the activation energy (Ea). How this energy compares to the kinetic energy provided by colliding reactant molecules is a primary factor affecting the rate of a chemical reaction. If the activation energy is much … Continue reading Activation Energy and the Arrhenius Equation
  • The Collision Theory
    The Collision Theory (OpenStax Chemistry 2e) We should not be surprised that atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This simple premise is the basis for a very powerful theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates. … Continue reading The Collision Theory
  • Reaction Rates in Analysis: Test Strips for Urinalysis
    Reaction Rates in Analysis: Test Strips for Urinalysis (OpenStax Chemistry 2e) Physicians often use disposable test strips to measure the amounts of various substances in a patient’s urine (Figure ). These test strips contain various chemical reagents, embedded in small pads at various locations along the strip, which undergo changes in color upon exposure to sufficient concentrations … Continue reading Reaction Rates in Analysis: Test Strips for Urinalysis
  • Glacier National Park: Apgar and Lake McDonald
    Apgar is a village located within the Glacier National Park at the south end portion of Lake McDonald. Situated two miles north of West Glacier, the village has a visitor center, gift shops, camp equipment store, restaurant, and lodging. Apgar is known for its spot to view some of the beautiful peaks of Glacier National Park with … Continue reading Glacier National Park: Apgar and Lake McDonald
  • US-2 Route Driving Scenery from East Glacier to West Glacier in Montana
    The drive along US-2 route from East Glacier to West Glacier in Montana takes about an hour and 5 minutes. In addition to the snowcapped peaks of Glacier National Park, good spots to pull over for a quick look include a waterfall, a wildlife overlook, and a river. The glittery Silver Staircase Waterfall is about 21 miles … Continue reading US-2 Route Driving Scenery from East Glacier to West Glacier in Montana
  • East Glacier and Lower Two Medicine Lake in Montana
    Begin your Western Montana escapade at East Glacier, one of the gateways to Glacier National Park. East Glacier is within the Blackfeet Indian Reservation and nearby areas have historical and cultural importance to the Blackfeet Tribe. There are hiking trails with glacier views, beautiful wildflowers, snowcapped peaks, and crystal clear mountain streams. The drive from Great Falls … Continue reading East Glacier and Lower Two Medicine Lake in Montana
  • Electrical Properties of Colloidal Particles
    Electrical Properties of Colloidal Particles (OpenStax Chemistry 2e) Dispersed colloidal particles are often electrically charged. A colloidal particle of iron(III) hydroxide, for example, does not contain enough hydroxide ions to compensate exactly for the positive charges on the iron(III) ions. Thus, each individual colloidal particle bears a positive charge, and the colloidal dispersion consists of charged colloidal … Continue reading Electrical Properties of Colloidal Particles
  • Deepwater Horizon Oil Spill
    Deepwater Horizon Oil Spill (OpenStax Chemistry 2e) The blowout of the Deepwater Horizon oil drilling rig on April 20, 2010, in the Gulf of Mexico near Mississippi began the largest marine oil spill in the history of the petroleum industry. In the 87 days following the blowout, an estimated 4.9 million barrels (210 million gallons) of oil … Continue reading Deepwater Horizon Oil Spill
  • Soaps and Detergents
    Soaps and Detergents (OpenStax Chemistry 2e) Pioneers made soap by boiling fats with a strongly basic solution made by leaching potassium carbonate, K2CO3, from wood ashes with hot water. Animal fats contain polyesters of fatty acids (long-chain carboxylic acids). When animal fats are treated with a base like potassium carbonate or sodium hydroxide, glycerol and salts of … Continue reading Soaps and Detergents
  • The Preparation of Colloidal Systems
    The Preparation of Colloidal Systems (OpenStax Chemistry 2e) Colloids are prepared by producing particles of colloidal dimensions and distributing these particles throughout a dispersion medium. Particles of colloidal size are formed by two methods: Dispersion methods: breaking down larger particles. For example, paint pigments are produced by dispersing large particles by grinding in special mills. Condensation methods: … Continue reading The Preparation of Colloidal Systems
  • Colloids
    Colloids (OpenStax Chemistry 2e) As a child, you may have made suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water, known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible (or that can be seen with a magnifying glass). They are cloudy, … Continue reading Colloids
  • Colligative Properties and De-Icing
    Colligative Properties and De-Icing (OpenStax Chemistry 2e) Sodium chloride and its group 2 analogs calcium and magnesium chloride are often used to de-ice roadways and sidewalks, due to the fact that a solution of any one of these salts will have a freezing point lower than 0 °C, the freezing point of pure water. The group 2 metal … Continue reading Colligative Properties and De-Icing
  • Research Highlights: CRISPR Editing Lowers LDL Cholesterol in Monkeys
    CRISPR Editing Lowers LDL Cholesterol in Monkeys CRISPR is a technology that has changed the way basic research is conducted and the way we can now think about disease treatment.[2] CRISPR can potentially modify genes that cause disease. Durable gene editing in target organs of non-human primates is a key step before the administration of gene editor … Continue reading Research Highlights: CRISPR Editing Lowers LDL Cholesterol in Monkeys
  • Colligative Properties of Electrolytes
    Colligative Properties of Electrolytes (OpenStax Chemistry 2e) The colligative properties of a solution depend only on the number, not on the identity, of solute species dissolved. The concentration terms in the equations for various colligative properties (freezing point depression, boiling point elevation, osmotic pressure) pertain to all solute species present in the solution. For the solutions considered thus … Continue reading Colligative Properties of Electrolytes
  • Osmosis and Osmotic Pressure of Solutions
    OpenStax Chemistry 2e A number of natural and synthetic materials exhibit selective permeation, meaning that only molecules or ions of a certain size, shape, polarity, charge, and so forth, are capable of passing through (permeating) the material. Biological cell membranes provide elegant examples of selective permeation in nature, while dialysis tubing used to remove metabolic wastes from blood … Continue reading Osmosis and Osmotic Pressure of Solutions
  • Phase Diagram for a Solution
    Phase Diagram for a Solution (OpenStax Chemistry 2e) The colligative effects on vapor pressure, boiling point, and freezing point described in the previous section are conveniently summarized by comparing the phase diagrams for a pure liquid and a solution derived from that liquid (Figure 1). The liquid-vapor curve for the solution is located beneath the corresponding curve for the … Continue reading Phase Diagram for a Solution
  • Freezing Point Depression
    Freezing Point Depression (OpenStax Chemistry 2e) Solutions freeze at lower temperatures than pure liquids. This phenomenon is exploited in “de-icing” schemes that use salt (Figure 1), calcium chloride, or urea to melt ice on roads and sidewalks, and in the use of ethylene glycol as an “antifreeze” in automobile radiators. Seawater freezes at a lower temperature than … Continue reading Freezing Point Depression
  • The Boiling Point Elevation
    The Boiling Point Elevation (OpenStax Chemistry 2e) The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases … Continue reading The Boiling Point Elevation
  • The Distillation of Solutions
    The Distillation of Solutions (OpenStax Chemistry 2e) Solutions whose components have significantly different vapor pressures may be separated by a selective vaporization process known as distillation. Consider the simple case of a mixture of two volatile liquids, A and B, with A being the more volatile liquid. Raoult’s law can be used to show that the vapor … Continue reading The Distillation of Solutions
  • Vapor Pressure Lowering
    Vapor Pressure Lowering (OpenStax Chemistry 2e) The equilibrium vapor pressure of a liquid is the pressure exerted by its gaseous phase when vaporization and condensation are occurring at equal rates: liquid⇌gas Dissolving a nonvolatile substance in a volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be rationalized by considering the effect … Continue reading Vapor Pressure Lowering
  • Research Highlights: COVID-19 mRNA Vaccines Activate Immune System in Pregnant and Lactating Women
    COVID-19 mRNA Vaccines Activate Immune System in Pregnant and Lactating Women Studies have shown that COVID-19 increases the risk for morbidity and mortality in pregnant women however, these women have not been included in phase 3 COVID-19 vaccine trials. As a result, information regarding the immunogenicity and vaccine safety in these group are lacking. Researchers evaluated the … Continue reading Research Highlights: COVID-19 mRNA Vaccines Activate Immune System in Pregnant and Lactating Women
  • (White Paper Sample) Light Promoter Elements: An Alternative To Conventional Chemical-Regulated Systems
    Disclaimer: This is not a peer-reviewed research white paper, but an example of white paper writing based on an undergraduate biotechnology course at California State University-San Marcos. Author: Benison P. Zerrudo ABSTRACT Microalgae have been an important organism in a wide range of industries. They are used in the production of biofuels, used in the food industry, … Continue reading (White Paper Sample) Light Promoter Elements: An Alternative To Conventional Chemical-Regulated Systems
  • Solutions of Solids in Liquids
    Solutions of Solids in Liquids (OpenStax Chemistry 2e) The dependence of solubility on temperature for a number of solids in water is shown by the solubility curves in Figure 1. Reviewing these data indicates a general trend of increasing solubility with temperature, although there are exceptions, as illustrated by the ionic compound cerium sulfate. The temperature dependence of … Continue reading Solutions of Solids in Liquids
  • Solutions of Liquids in Liquids
    Solutions of Liquids in Liquids (OpenStax Chemistry 2e) Some liquids may be mixed in any proportions to yield solutions; in other words, they have infinite mutual solubility and are said to be miscible. Ethanol, sulfuric acid, and ethylene glycol (popular for use as antifreeze, pictured in Figure 1) are examples of liquids that are completely miscible with water. Two-cycle … Continue reading Solutions of Liquids in Liquids
  • Solutions of Gases in Liquids
    Solutions of Gases in Liquids (OpenStax Chemistry 2e) As for any solution, the solubility of a gas in a liquid is affected by the intermolecular attractive forces between solute and solvent species. Unlike solid and liquid solutes, however, there is no solute-solute intermolecular attraction to overcome when a gaseous solute dissolves in a liquid solvent since the … Continue reading Solutions of Gases in Liquids
  • Ionic Electrolytes
    Ionic Electrolytes (OpenStax Chemistry 2e) Water and other polar molecules are attracted to ions, as shown in Figure 1. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water. When ionic compounds dissolve in water, the ions in … Continue reading Ionic Electrolytes
  • Unit Cells of Ionic Compounds
    Unit Cells of Ionic Compounds (OpenStax Chemistry 2e) Many ionic compounds crystallize with cubic unit cells, and we will use these compounds to describe the general features of ionic structures. When an ionic compound is composed of cations and anions of similar size in a 1:1 ratio, it typically forms a simple cubic structure. Cesium chloride, CsCl, … Continue reading Unit Cells of Ionic Compounds
  • X-Ray Crystallography
    X-Ray Crystallography (OpenStax Chemistry 2e) The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography. Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of … Continue reading X-Ray Crystallography
  • X-ray Crystallographer Rosalind Franklin
    X-ray Crystallographer Rosalind Franklin (OpenStax Chemistry 2e) The discovery of the structure of DNA in 1953 by Francis Crick and James Watson is one of the great achievements in the history of science. They were awarded the 1962 Nobel Prize in Physiology or Medicine, along with Maurice Wilkins, who provided experimental proof of DNA’s structure. British chemist Rosalind Franklin made invaluable contributions to this … Continue reading X-ray Crystallographer Rosalind Franklin
  • The Dissolution Process
    The Dissolution Process (OpenStax Chemistry 2e) Solutions defined as homogeneous mixtures of two or more substances. Often, one component of a solution is present at a significantly greater concentration, in which case it is called the solvent. The other components of the solution present in relatively lesser concentrations are called solutes. Sugar is a covalent solid composed of sucrose … Continue reading The Dissolution Process